ORCID Profile
0000-0003-3159-5396
Current Organisation
University of California, San Diego
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Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2011
Publisher: Springer Science and Business Media LLC
Date: 25-04-2012
Publisher: Elsevier BV
Date: 08-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5RA22441A
Abstract: The role of cations and anions of ionic liquids in the destabilization of collagen has been elucidated.
Publisher: Wiley
Date: 07-03-2021
Abstract: Neurological disorders such as Alzheimer's disease, stroke, and brain cancers are difficult to treat with current drugs as their delivery efficacy to the brain is severely h ered by the presence of the blood–brain barrier (BBB). Drug delivery systems have been extensively explored in recent decades aiming to circumvent this barrier. In particular, polymeric nanoparticles have shown enormous potentials owing to their unique properties, such as high tunability, ease of synthesis, and control over drug release profile. However, careful analysis of their performance in effective drug transport across the BBB should be performed using clinically relevant testing models. In this review, polymeric nanoparticle systems for drug delivery to the central nervous system are discussed with an emphasis on the effects of particle size, shape, and surface modifications on BBB penetration. Moreover, the authors critically analyze the current in vitro and in vivo models used to evaluate BBB penetration efficacy, including the latest developments in the BBB‐on‐a‐chip models. Finally, the challenges and future perspectives for the development of polymeric nanoparticles to combat neurological disorders are discussed.
Publisher: Elsevier BV
Date: 08-2014
DOI: 10.1016/J.IJBIOMAC.2014.05.021
Abstract: "Go Green" c aign is gaining light for various industrial applications where water consumption needs to be reduced. To resolve this, industries have adopted usage of green, organic solvents, as an alternative to water. For leather making, tanning industry consumes gallons of water. Therefore, for adopting green solvents in leather making, it is necessary to evaluate its influence on type I collagen, the major protein present in the skin matrix. The thermal stability of collagen from rat tail tendon fiber (RTT) treated with seven green solvents namely, ethanol, ethyl lactate, ethyl acetate, propylene carbonate, propylene glycol, polyethylene glycol-200 and heptane was determined using differential scanning calorimetry (DSC). Crosslinking efficiency of basic chromium sulfate and wattle on RTT in green solvents was determined. DSC thermograms show increase in thermal stability of RTT collagen against heat with green solvents (>78°C) compared to water (63°C). In the presence of crosslinkers, RTT demonstrated thermal stability >100°C in some green solvents, resulting in increased intermolecular forces between collagen, solvent and crosslinkers. The significant improvement in thermal stability of collagen potentiates the capability of green solvents as an alternative for water.
Publisher: SAGE Publications
Date: 19-01-2015
Abstract: This study describes the microenvironmental changes due to various non-covalent interactions occurring in collagen olyvinyl alcohol blends in the presence of ionic liquid, 1-butyl-3-methylimidazolium chloride, using spectroscopic techniques. These non-covalent interactions alter the hydration network of collagen. Electronic spectral analysis of collagen olyvinyl alcohol/ionic liquid blends exhibited movement of tyrosine amino acid from the hydrophilic to hydrophobic core of collagen. Conformational studies investigating the influence of 1-butyl-3-methylimidazolium chloride on the intramolecular H-bonds revealed increased helicity packing and reorientation of H-bonds. This signifies that 1-butyl-3-methylimidazolium chloride is likely to be involved in reorienting the hydration dynamics of collagen, namely, by altering the existing and promoting formation of new intramolecular H-bonds between collagen and polyvinyl alcohol. Surface morphology of collagen olyvinyl alcohol/ionic liquid blends revealed porous matrix, indicating 1-butyl-3-methylimidazolium chloride could act as a pore generator. This phenomenon can be employed for developing novel biomaterials with tunable porosity.
Publisher: Wiley
Date: 23-08-2022
Abstract: A continuous, sealed endothelial membrane is essential for the blood–brain barrier (BBB) to protect neurons from toxins present in systemic circulation. Endothelial cells are critical sensors of the capillary environment, where factors like fluid shear stress (FSS) and systemic signaling molecules activate intracellular pathways that either promote or disrupt the BBB. The brain vasculature exhibits complex heterogeneity across the bed, which is challenging to recapitulate in BBB microfluidic models with fixed dimensions and rectangular cross‐section microchannels. Here, a Cayley‐tree pattern, fabricated using lithography‐less, fluid shaping technique in a modified Hele‐Shaw cell is used to emulate the brain vasculature in a microfluidic chip. This geometry generates an inherent distribution of heterogeneous FSS, due to smooth variations in branch height and width. hCMEC/D3 endothelial cells cultured in the Cayley‐tree designed chip generate a 3D monolayer of brain endothelium with branching hierarchy, enabling the study of the effect of heterogeneous FSS on the brain endothelium. The model is employed to study neuroinflammatory conditions by stimulating the brain endothelium with tumor necrosis factor‐α under heterogeneous FSS conditions. The model has immense potential for studies involving drug transport across the BBB, which can be misrepresented in fixed dimension models.
Publisher: American Chemical Society (ACS)
Date: 28-09-2015
Abstract: Cross-linkers aid in improving biostability of collagen via different mechanisms. Choline dihydrogen phosphate (cDHP), a biocompatible ionic liquid, has been reported as a potential cross-linker for collagen. However, its mechanism is yet unclear. This study explores the effect of cDHP on the physicochemical stability of collagen and nature of its interaction. Dielectric behavior of collagen-cDHP composites signifies that cDHP enhances intermolecular forces. This was demonstrated by an increase in cross-linked groups and high denaturation temperature of collagen-cDHP composites. XRD measurements reveal minor conformational change in helices. Molecular modeling studies illustrate that the force existing between collagen and cDHP is electrostatic in nature. Herein, it is postulated that dihydrogen phosphate anion attaches to cationic functional groups of collagen, resulting in closer vicinity of various side chains of collagen, forming physical and chemical cross-links within collagen, contributing to its structural stability. Our study suggests that dihydrogen phosphate anions can be employed for developing a new class of biocompatible cross-linkers.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA02167G
Abstract: The manufacture of leather is a challenging and complicated process, which converts natural biomaterial to various high end applications.
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.COLSURFB.2014.03.014
Abstract: The effect of ionic liquids (ILs) on proteins has been gaining huge interest due to easy tunability of cation and anion for generating the desired effect. This study explores the effect of alkyl imidazolium chloride ILs on collagen at molecular, inter-fibrillar and skin matrix level. Circular dichroic studies reveal that at the molecular level, the secondary structure of collagen was not affected by imidazolium ILs and there was no change in thermal stability as well. However, collagen at the inter-fibrillar level behaved differently. With increase in concentration of ILs, remarkable decrease in thermal stability of rat tail tendon (RTT) collagen fibers with marginal swelling effect was seen. SEM micrographs of skin matrix treated with IL show opening up of pores. This kind of exquisite behavior of ILs at different hierarchal order of collagen indicates that ILs are endowed with potential lyotropic action, which can be judiciously employed for biomedical applications.
Publisher: American Chemical Society (ACS)
Date: 29-06-2016
Abstract: Ions play a key role in the destabilization of collagen. This study explores the effect of diethyl methyl ammonium methane sulfonate (AMS), an ionic liquid (IL), on different hierarchical orderings of collagen, namely, at the molecular and fibrillar levels. The rheological behavior and secondary structural changes reveal changes in the hydrogen-bonding environment of collagen, leading to alterations in the triple helical structure of collagen. An increase in the concentration of AMS resulted in swelling of rat-tail tendon fibers, and also, decreased thermal stability signifies that ions are obliged to destabilize collagen at the fibrillar level. Molecular modeling studies confirm that anions are judiciously held responsible for structural deformities in collagen, whereas cations have a tenuous effect. Thus, the preferential role of ions present in an ammonium IL has been elucidated in this study.
Location: United States of America
No related grants have been discovered for Ami Mehta-Doshi.